Formation of polymers from various monomers for creating drag reducing polymer is a well-known art. As is also well known in the art, the polymerization reactor in which the polymers are formed from the monomers have certain inherent limitations to efficiently form the polymers. A major inherent limitation is the removal of heat from the polymerization reactor created by the chemical reaction between the monomers and the catalyst during formation of the drag reducing polymers. To overcome this problem, cooling systems have been designed to encase the polymerization reactor in an attempt to remove the heat from the polymerization reactor. Additionally, cooling additives may be included in the polymerization reaction mixture in the polymerization reactor. Still further, extremely small reactors have been used to increase the surface area per unit mass, and such small reactors have been in the form of plastic bags.
All of these prior attempts, however, have various shortcomings. For example, the use of cooling systems outside the polymerization reactor do not efficiently and effectively remove heat from the polymerization reactor, especially for the center most region of the polymerization reactor. Accordingly, the size of the polymerization reactor must be small and limited amounts of polymer may be formed in each reactor batch. Additionally, with respect to the addition of cooling additives to the polymerization reactants, these cooling additives can have an adverse effect on the quality of the drag reducing polymer as well as increasing the cost associated with forming the polymer.
In other prior attempts, as discussed in U.S. Pat. Nos. 5,449,732, 5,504,131, and 5,504,132, the polymerization reactor is a crystalline, hydrocarbon-insoluble organic polymer reaction enclosure capable of substantially preventing passage of oxygen and water, i.e., plastic bags. Use of these plastic bags permits the polymerization reaction to be carried out without a cooling system or addition of cooling additives. However, because the plastic bags are not provided with any assistance in the removal of heat from the polymerization reaction, only small amounts of polymer reactants, e.g., monomer and catalyst, can be included in each plastic bag. As such, only small amounts of drag reducing polymer can be formed in each of this type of polymerization reactor. Further, the plastic bags cannot be easily separated from the drag-reducing polymer, and thus, the plastic bags and the drag-reducing polymer are typically merged or ground together into the final DRA product. Thus, the making of the drag-reducing polymer creates a polymer that is contaminated with its own manufacturing process. Such drag-reducing polymer is not readily useable in, for example, product pipelines because of the contamination caused by the bag particles. Further, such known procedures for manufacturing drag reducing polymer require the enclosure of the polymer in an environment that prevents the reaction of the DRA polymer with unwanted reactants; thus the use of the plastic bags. But the use of plastic bags limits the mass of product that can be made in one bag because the reaction is exothermic, and if not controlled, then an effective DRA product is destroyed during its manufacture.
Accordingly, prior to the development of the present invention, there has been no polymerization reactor or process for forming drag reducing polymers, which: effectively remove heat away from the polymerization reactor; permit the formation of a large amount of drag reducing polymer in each polymerization reactor; do not require the addition of cooling additives; can create pristine DRA without contaminates such as for example plastic bag particles; is isolated in an environment that enhances the creation and preservation of highly effective DRA product; and permit the use of a re-useable polymerization reactor. Therefore, the art has sought a polymerization reactor and a process for forming drag reducing polymers, which: effectively remove heat away from the polymerization reactor; permit the formation of a large amount of polymer in each polymerization reactor; do not require the addition of cooling additives; and permit the use of a re-useable polymerization reactor.
It is, therefore, a feature of the present invention to provide a reactor and method that creates highly effective DRA polymer.
A feature of the present invention is to provide an effective DRA reactor and method that effectively removes heat from the DRA polymerization reactor.
Another feature of the present invention is to provide an effective DRA reactor and method that permits the formation of a large amount of polymer in each polymerization reactor.
Another feature of the present invention is to provide an effective DRA reactor and method that does not require the addition of cooling additives.
Another feature of the present invention is to provide an effective DRA reactor and method that permits the use of a re-useable polymerization reactor.
Yet another feature of the invention is to provide an effective DRA reactor and method that has better plastic bag release characteristics.
Still another feature of the present invention is utilizing an effective DRA reactor and method that creates pristine DRA product.
Another feature of the present invention is to provide an effective DRA reactor and method that assists in reducing the formation of or assisting the elimination of nonfunctional polymers or unreacted olefins from the process.
Yet another feature of the present invention is to provide an effective DRA reactor and method that removes contaminants from DRA reactor before initiating the reaction process.
Another feature of the present invention is to provide an effective DRA reactor and method that prevents contaminants from entering during the reaction process.
Yet another feature of the present invention is to provide an effective DRA reactor and method that can be adjusted during the polymerization process to compensate for the inadvertent addition of unwanted contaminates such as by way of example and without limitation ambient air entering due to faulty sealing along any of the joining parts.
Still another feature of the present invention is to provide an effective DRA reactor and method that removes the unwanted moisture from the reactor continuously during the polymerization process.
Yet still another feature of the present invention to provide an effective DRA reactor and method with nitrogen ports and valves to fully purge ambient air from the system for eliminating any contaminants prior to loading the reactant mixture.
Yet further, an additional feature of the present invention to provide an effective DRA reactor and method with valves on the nitrogen ports to control the flow of nitrogen into the reactor as well as out of the reactor, whereby partially closing the exhaust valve allows a slight positive pressure within the reactant chamber, which positive pressure compensates for any defects in the sealing system, and nitrogen will exhaust out of any faulty seals thereby preventing any contaminants from entering.
Yet another feature of the present invention is to provide an effective DRA reactor and method such that the bases can be fixedly attached or removable depending on which removal process is used.
Still further another feature of the present invention is to provide an effective DRA reactor and method where the plate separation can be adjusted according to the anticipated reaction process temperature.
Yet another feature of the present invention is to provide an effective DRA reactor and method that provides carbon steel cavities and exchanger plates where the surfaces are not treated, but allowed to form a thin layer of rust which acts as a lubricant allowing a plastic bag type removable film to slip out easier.
Yet still another feature of the present invention is to provide an effective DRA reactor and method that provides an effective DRA reactor and method that requires only inexpensive and/or basic sealing mechanisms between the lid, walls and base as the slightly positive nitrogen pressure in the system compensates for any defects or damaged seal points.
Yet still another feature of the present invention is to provide an effective DRA reactor and method that provides that the exchanger plates are not fixed to the lid but rather slid onto a guide attached to the lid allowing adjustment to the separation between plates if needed whereby the plates are then connected via flexible conduit to the coolant manifold.
Additional features and advantages of the invention will be set forth in part in the description which follows, and in part will become apparent from the description, or may be learned by practice of the invention. The features and advantages of the invention may be realized by means of the combinations and steps particularly pointed out in the appended claims.